3Environmental Monitoring Network, faculty of Science, University of Oran, ALGERIA

Corresponding author: bouhadidjilali@yahoo.fr

Abstract. Lactic acid production from renewable resources such as pods of carob alternate to derived products from oil present a growing interest, in particular for the production of biodegradable polylactic acid polymer. The carob pods syrup is a by–product composed of sugars and its use as substrate of low cost in various industries is considered however, few microorganisms consume quickly and effectively sugars to give a single product. Lactic acid bacteria were screened for sugars fermentation and Lactobacillus delbrueckii subsp. bulgaricus showed the highest levels of lactic acid production. The physicochemical analysis of carob pods syrup showed that it presents a suitable quality. The micro–organism implemented is kind Lactobacillus delbrueckii subsp. bulgaricus, cultivated in bathe fermentation. Three culture mediums were tested, the carob syrup enriched with sweet cheese whey (CS+SCW), carob syrup enriched with Tween80 (CS+T80) and carob syrup enriched with sweet cheese whey+Tween80 (CS+SCW+T80), the addition of the growth factors improve the culture, that is why the production of lactate is very important improved 52.76 g/l.